Low-Dose Aspirin Increases Cancer Survival Rate By 20 Percent

A new study suggests low-dose aspirin taken during cancer treatment could increase survival by 20 percent. Gary Cameron/REUTERS

Aspirin is prized by many people for effectively treating occasional aches, pain and fever, and physicians hold up the drug as a top line defense for heart attack and stroke. Now, a new study suggests this relatively innocuous over-the-counter medication should also be charged with another role: cancer-fighter.

A study published April 20 in PLOS ONE finds taking low-dose aspirin while undergoing cancer treatment may increase a patient's chance of survival by as much as 20 percent.

For the study, a team of researchers looked at the available scientific literature on aspirin maintenance therapy—taking a daily low dose, typically between 80 and 325 milligrams—in cancer treatment. This included five randomized trials and 42 observational studies on patients with breast, prostate and colorectal cancers. The average study had a follow-up period of five years.

Overall, the researchers found there was a significant reduction in mortality in patients who took daily low-dose aspirin. The aspirin also appeared to keep the cancer from spreading.

However, it's still too early to say whether the drug can provide an extra boost in treating every type of cancer. If anything, this analysis indicates that many additional randomized trials are desperately needed to study the drug's effects more closely on specific cancers. For example, there currently are only single studies that show aspirin improves outcomes for esophageal cancer, lymphatic leukemia and lung cancer.

But what is known fairly well is that not all cancer patients will benefit from aspirin therapy. A study published in The New England Journal of Medicine, and included in the new analysis in PLOS ONE, found only colorectal cancer patients with mutations to the PIK3CA gene had improved prognosis due to aspirin compared with those who did not have mutations to that gene.

Other studies suggest low-dose aspirin is effective for cancer prevention. In 2012, The Lancet published an analysis of 51 randomized clinical trials that found aspirin reduced incidence of cancer by about 24 percent after just three years of taking the drug and reduced cancer deaths by 37 percent after five years when compared to people not taking a daily aspirin dose.

Aspirin is sometimes recommended to cancer patients because chemotherapy can cause blood clots. While it is a relatively low-risk drug, it does come with some risks. Long-term use can cause gastrointestinal bleeding. Aspirin also increases the risk for fatal cerebral bleeding. Approximately 1 in 10,000 people dies each year from a stroke caused by an aspirin-related brain bleed. However, aspirin's protective benefits for heart disease and cancer far outweigh the potential risks posed by the drug.